Scientists use bacteria to break malaria’s infection chain

WASHINGTON – U.S. scientists have found a way to infect mosquitoes with bacteria to break the chain of malaria transmission, according to research published Thursday.

A similar approach has helped reduce dengue fever in some locations, and researchers hope the findings can offer a path toward reducing malaria among the most common mosquitoes in the Middle East and South Asia.

Scientists injected Anopheles mosquito embryos with Wolbachia, a common insect bacterium. When the mosquitoes matured, adult females were bred with uninfected males. The infection renders mosquitoes immune to malaria parasites and can be passed on, reported experts from the National Institutes of Health in the journal Science. The infection endured for 34 generations of mosquitoes. The study ended at that point, so it remains unknown how much longer the bacterial infection would have been passed on, preventing malaria transmission.

The infection killed malaria parasites both in the mosquitoes’ guts and in the salivary glands, the main avenue for transmission to humans via mosquito bites.

Researchers also tried introducing the bacterial infection to small numbers of adult mosquitoes, between 5 and 20 percent of females in a given population. Within eight generations, all of the mosquitoes were infected with the malaria-blocking infection.

The evidence supports the “potential of Wolbachia-infected mosquitoes as a malaria control strategy,” said the study.